I don't believe so. The thing is, MS AJAX cannot load the scripts of IScriptControl objects when output caching is enabled. This means that, if you have a user control with output caching enabled inside an AJAX container, on the next AJAX postback, controls inside the user control will not be initialized if the user control itself is cached. This also means controls will not register their client scripts. MS AJAX expects that IScriptControl instances register their required scripts on every AJAX postback. Output caching violates this requirement and breaks the behavior of your controls. You do not get the client components of your script controls re-initialized on AJAX when a parent user control has been cached.
Veli
the Telerik team